#region Apache License
//
// Licensed to the Apache Software Foundation (ASF) under one or more 
// contributor license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright ownership. 
// The ASF licenses this file to you under the Apache License, Version 2.0
// (the "License"); you may not use this file except in compliance with 
// the License. You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
#endregion

// .NET Compact Framework 1.0 has no support for reading assembly attributes
#if !NETCF

using log4net.Repository;
using log4net.Repository.Hierarchy;
using log4net.Util;
using System;
using System.Collections;
using System.IO;
using System.Reflection;

namespace log4net.Config
{
    /// <summary>
    /// Assembly level attribute to configure the <see cref="XmlConfigurator"/>.
    /// </summary>
    /// <remarks>
    /// <para>
    /// This attribute may only be used at the assembly scope and can only
    /// be used once per assembly.
    /// </para>
    /// <para>
    /// Use this attribute to configure the <see cref="XmlConfigurator"/>
    /// without calling one of the <see cref="XmlConfigurator.Configure()"/>
    /// methods.
    /// </para>
    /// <para>
    /// If neither of the <see cref="ConfigFile"/> or <see cref="ConfigFileExtension"/>
    /// properties are set the configuration is loaded from the application's .config file.
    /// If set the <see cref="ConfigFile"/> property takes priority over the
    /// <see cref="ConfigFileExtension"/> property. The <see cref="ConfigFile"/> property
    /// specifies a path to a file to load the config from. The path is relative to the
    /// application's base directory; <see cref="AppDomain.BaseDirectory"/>.
    /// The <see cref="ConfigFileExtension"/> property is used as a postfix to the assembly file name.
    /// The config file must be located in the  application's base directory; <see cref="AppDomain.BaseDirectory"/>.
    /// For example in a console application setting the <see cref="ConfigFileExtension"/> to
    /// <c>config</c> has the same effect as not specifying the <see cref="ConfigFile"/> or 
    /// <see cref="ConfigFileExtension"/> properties.
    /// </para>
    /// <para>
    /// The <see cref="Watch"/> property can be set to cause the <see cref="XmlConfigurator"/>
    /// to watch the configuration file for changes.
    /// </para>
    /// <note>
    /// <para>
    /// Log4net will only look for assembly level configuration attributes once.
    /// When using the log4net assembly level attributes to control the configuration 
    /// of log4net you must ensure that the first call to any of the 
    /// <see cref="log4net.Core.LoggerManager"/> methods is made from the assembly with the configuration
    /// attributes. 
    /// </para>
    /// <para>
    /// If you cannot guarantee the order in which log4net calls will be made from 
    /// different assemblies you must use programmatic configuration instead, i.e.
    /// call the <see cref="XmlConfigurator.Configure()"/> method directly.
    /// </para>
    /// </note>
    /// </remarks>
    /// <author>Nicko Cadell</author>
    /// <author>Gert Driesen</author>
    [AttributeUsage(AttributeTargets.Assembly)]
    [Serializable]
    public /*sealed*/ class XmlConfiguratorAttribute : ConfiguratorAttribute
    {
        //
        // Class is not sealed because DOMConfiguratorAttribute extends it while it is obsoleted
        // 

        /// <summary>
        /// Default constructor
        /// </summary>
        /// <remarks>
        /// <para>
        /// Default constructor
        /// </para>
        /// </remarks>
        public XmlConfiguratorAttribute() : base(0) /* configurator priority 0 */
        {
        }

        #region Public Instance Properties

        /// <summary>
        /// Gets or sets the filename of the configuration file.
        /// </summary>
        /// <value>
        /// The filename of the configuration file.
        /// </value>
        /// <remarks>
        /// <para>
        /// If specified, this is the name of the configuration file to use with
        /// the <see cref="XmlConfigurator"/>. This file path is relative to the
        /// <b>application base</b> directory (<see cref="AppDomain.BaseDirectory"/>).
        /// </para>
        /// <para>
        /// The <see cref="ConfigFile"/> takes priority over the <see cref="ConfigFileExtension"/>.
        /// </para>
        /// </remarks>
        public string ConfigFile
        {
            get { return m_configFile; }
            set { m_configFile = value; }
        }

        /// <summary>
        /// Gets or sets the extension of the configuration file.
        /// </summary>
        /// <value>
        /// The extension of the configuration file.
        /// </value>
        /// <remarks>
        /// <para>
        /// If specified this is the extension for the configuration file.
        /// The path to the config file is built by using the <b>application 
        /// base</b> directory (<see cref="AppDomain.BaseDirectory"/>),
        /// the <b>assembly file name</b> and the config file extension.
        /// </para>
        /// <para>
        /// If the <see cref="ConfigFileExtension"/> is set to <c>MyExt</c> then
        /// possible config file names would be: <c>MyConsoleApp.exe.MyExt</c> or
        /// <c>MyClassLibrary.dll.MyExt</c>.
        /// </para>
        /// <para>
        /// The <see cref="ConfigFile"/> takes priority over the <see cref="ConfigFileExtension"/>.
        /// </para>
        /// </remarks>
        public string ConfigFileExtension
        {
            get { return m_configFileExtension; }
            set { m_configFileExtension = value; }
        }

        /// <summary>
        /// Gets or sets a value indicating whether to watch the configuration file.
        /// </summary>
        /// <value>
        /// <c>true</c> if the configuration should be watched, <c>false</c> otherwise.
        /// </value>
        /// <remarks>
        /// <para>
        /// If this flag is specified and set to <c>true</c> then the framework
        /// will watch the configuration file and will reload the config each time 
        /// the file is modified.
        /// </para>
        /// <para>
        /// The config file can only be watched if it is loaded from local disk.
        /// In a No-Touch (Smart Client) deployment where the application is downloaded
        /// from a web server the config file may not reside on the local disk
        /// and therefore it may not be able to watch it.
        /// </para>
        /// <note>
        /// Watching configuration is not supported on the SSCLI.
        /// </note>
        /// </remarks>
        public bool Watch
        {
            get { return m_configureAndWatch; }
            set { m_configureAndWatch = value; }
        }

        #endregion Public Instance Properties

        #region Override ConfiguratorAttribute

        /// <summary>
        /// Configures the <see cref="ILoggerRepository"/> for the specified assembly.
        /// </summary>
        /// <param name="sourceAssembly">The assembly that this attribute was defined on.</param>
        /// <param name="targetRepository">The repository to configure.</param>
        /// <remarks>
        /// <para>
        /// Configure the repository using the <see cref="XmlConfigurator"/>.
        /// The <paramref name="targetRepository"/> specified must extend the <see cref="Hierarchy"/>
        /// class otherwise the <see cref="XmlConfigurator"/> will not be able to
        /// configure it.
        /// </para>
        /// </remarks>
        /// <exception cref="ArgumentOutOfRangeException">The <paramref name="targetRepository" /> does not extend <see cref="Hierarchy"/>.</exception>
        override public void Configure(Assembly sourceAssembly, ILoggerRepository targetRepository)
        {
            IList configurationMessages = new ArrayList();

            using (new LogLog.LogReceivedAdapter(configurationMessages))
            {
                string applicationBaseDirectory = null;
                try
                {
                    applicationBaseDirectory = SystemInfo.ApplicationBaseDirectory;
                }
                catch
                {
                    // Ignore this exception because it is only thrown when ApplicationBaseDirectory is a file
                    // and the application does not have PathDiscovery permission
                }

                if (applicationBaseDirectory == null || (new Uri(applicationBaseDirectory)).IsFile)
                {
                    ConfigureFromFile(sourceAssembly, targetRepository);
                }
                else
                {
                    ConfigureFromUri(sourceAssembly, targetRepository);
                }
            }

            targetRepository.ConfigurationMessages = configurationMessages;
        }

        #endregion

        /// <summary>
        /// Attempt to load configuration from the local file system
        /// </summary>
        /// <param name="sourceAssembly">The assembly that this attribute was defined on.</param>
        /// <param name="targetRepository">The repository to configure.</param>
        private void ConfigureFromFile(Assembly sourceAssembly, ILoggerRepository targetRepository)
        {
            // Work out the full path to the config file
            string fullPath2ConfigFile = null;

            // Select the config file
            if (m_configFile == null || m_configFile.Length == 0)
            {
                if (m_configFileExtension == null || m_configFileExtension.Length == 0)
                {
                    // Use the default .config file for the AppDomain
                    try
                    {
                        fullPath2ConfigFile = SystemInfo.ConfigurationFileLocation;
                    }
                    catch (Exception ex)
                    {
                        LogLog.Error(declaringType, "XmlConfiguratorAttribute: Exception getting ConfigurationFileLocation. Must be able to resolve ConfigurationFileLocation when ConfigFile and ConfigFileExtension properties are not set.", ex);
                    }
                }
                else
                {
                    // Force the extension to start with a '.'
                    if (m_configFileExtension[0] != '.')
                    {
                        m_configFileExtension = "." + m_configFileExtension;
                    }

                    string applicationBaseDirectory = null;
                    try
                    {
                        applicationBaseDirectory = SystemInfo.ApplicationBaseDirectory;
                    }
                    catch (Exception ex)
                    {
                        LogLog.Error(declaringType, "Exception getting ApplicationBaseDirectory. Must be able to resolve ApplicationBaseDirectory and AssemblyFileName when ConfigFileExtension property is set.", ex);
                    }

                    if (applicationBaseDirectory != null)
                    {
                        fullPath2ConfigFile = Path.Combine(applicationBaseDirectory, SystemInfo.AssemblyFileName(sourceAssembly) + m_configFileExtension);
                    }
                }
            }
            else
            {
                string applicationBaseDirectory = null;
                try
                {
                    applicationBaseDirectory = SystemInfo.ApplicationBaseDirectory;
                }
                catch (Exception ex)
                {
                    LogLog.Warn(declaringType, "Exception getting ApplicationBaseDirectory. ConfigFile property path [" + m_configFile + "] will be treated as an absolute path.", ex);
                }

                if (applicationBaseDirectory != null)
                {
                    // Just the base dir + the config file
                    fullPath2ConfigFile = Path.Combine(applicationBaseDirectory, m_configFile);
                }
                else
                {
                    fullPath2ConfigFile = m_configFile;
                }
            }

            if (fullPath2ConfigFile != null)
            {
                ConfigureFromFile(targetRepository, new FileInfo(fullPath2ConfigFile));
            }
        }

        /// <summary>
        /// Configure the specified repository using a <see cref="FileInfo"/>
        /// </summary>
        /// <param name="targetRepository">The repository to configure.</param>
        /// <param name="configFile">the FileInfo pointing to the config file</param>
        private void ConfigureFromFile(ILoggerRepository targetRepository, FileInfo configFile)
        {
#if (SSCLI)
			if (m_configureAndWatch)
			{
				LogLog.Warn(declaringType, "XmlConfiguratorAttribute: Unable to watch config file not supported on SSCLI");
			}
			XmlConfigurator.Configure(targetRepository, configFile);
#else
            // Do we configure just once or do we configure and then watch?
            if (m_configureAndWatch)
            {
                XmlConfigurator.ConfigureAndWatch(targetRepository, configFile);
            }
            else
            {
                XmlConfigurator.Configure(targetRepository, configFile);
            }
#endif
        }

        /// <summary>
        /// Attempt to load configuration from a URI
        /// </summary>
        /// <param name="sourceAssembly">The assembly that this attribute was defined on.</param>
        /// <param name="targetRepository">The repository to configure.</param>
        private void ConfigureFromUri(Assembly sourceAssembly, ILoggerRepository targetRepository)
        {
            // Work out the full path to the config file
            Uri fullPath2ConfigFile = null;

            // Select the config file
            if (m_configFile == null || m_configFile.Length == 0)
            {
                if (m_configFileExtension == null || m_configFileExtension.Length == 0)
                {
                    string systemConfigFilePath = null;
                    try
                    {
                        systemConfigFilePath = SystemInfo.ConfigurationFileLocation;
                    }
                    catch (Exception ex)
                    {
                        LogLog.Error(declaringType, "XmlConfiguratorAttribute: Exception getting ConfigurationFileLocation. Must be able to resolve ConfigurationFileLocation when ConfigFile and ConfigFileExtension properties are not set.", ex);
                    }

                    if (systemConfigFilePath != null)
                    {
                        Uri systemConfigFileUri = new Uri(systemConfigFilePath);

                        // Use the default .config file for the AppDomain
                        fullPath2ConfigFile = systemConfigFileUri;
                    }
                }
                else
                {
                    // Force the extension to start with a '.'
                    if (m_configFileExtension[0] != '.')
                    {
                        m_configFileExtension = "." + m_configFileExtension;
                    }

                    string systemConfigFilePath = null;
                    try
                    {
                        systemConfigFilePath = SystemInfo.ConfigurationFileLocation;
                    }
                    catch (Exception ex)
                    {
                        LogLog.Error(declaringType, "XmlConfiguratorAttribute: Exception getting ConfigurationFileLocation. Must be able to resolve ConfigurationFileLocation when the ConfigFile property are not set.", ex);
                    }

                    if (systemConfigFilePath != null)
                    {
                        UriBuilder builder = new UriBuilder(new Uri(systemConfigFilePath));

                        // Remove the current extension from the systemConfigFileUri path
                        string path = builder.Path;
                        int startOfExtension = path.LastIndexOf(".");
                        if (startOfExtension >= 0)
                        {
                            path = path.Substring(0, startOfExtension);
                        }
                        path += m_configFileExtension;

                        builder.Path = path;
                        fullPath2ConfigFile = builder.Uri;
                    }
                }
            }
            else
            {
                string applicationBaseDirectory = null;
                try
                {
                    applicationBaseDirectory = SystemInfo.ApplicationBaseDirectory;
                }
                catch (Exception ex)
                {
                    LogLog.Warn(declaringType, "Exception getting ApplicationBaseDirectory. ConfigFile property path [" + m_configFile + "] will be treated as an absolute URI.", ex);
                }

                if (applicationBaseDirectory != null)
                {
                    // Just the base dir + the config file
                    fullPath2ConfigFile = new Uri(new Uri(applicationBaseDirectory), m_configFile);
                }
                else
                {
                    fullPath2ConfigFile = new Uri(m_configFile);
                }
            }

            if (fullPath2ConfigFile != null)
            {
                if (fullPath2ConfigFile.IsFile)
                {
                    // The m_configFile could be an absolute local path, therefore we have to be
                    // prepared to switch back to using FileInfos here
                    ConfigureFromFile(targetRepository, new FileInfo(fullPath2ConfigFile.LocalPath));
                }
                else
                {
                    if (m_configureAndWatch)
                    {
                        LogLog.Warn(declaringType, "XmlConfiguratorAttribute: Unable to watch config file loaded from a URI");
                    }
                    XmlConfigurator.Configure(targetRepository, fullPath2ConfigFile);
                }
            }
        }

        #region Private Instance Fields

        private string m_configFile = null;
        private string m_configFileExtension = null;
        private bool m_configureAndWatch = false;

        #endregion Private Instance Fields

        #region Private Static Fields

        /// <summary>
        /// The fully qualified type of the XmlConfiguratorAttribute class.
        /// </summary>
        /// <remarks>
        /// Used by the internal logger to record the Type of the
        /// log message.
        /// </remarks>
        private readonly static Type declaringType = typeof(XmlConfiguratorAttribute);

        #endregion Private Static Fields
    }
}

#endif // !NETCF
